photosynthesis

• what is photosynthesis 


  a chemical reaction that takes place inside photosyntheic organisms (plants , algae) , converting light energy into chemical energy
• word equation for photosynthesis

  carbon dioxide + water = glucose + oxygen
• symbol equation for photosynthesis

  6c02 + 6h20 = c6h12o6 + 6o2
• why is photosynthesis important 


  it produces glucose which has a wide range of uses
• what are 3 uses of glucose

  used in respiration to release energy ,

  converted to starch and stored - broken down into glucose when the plants requires energy

  is used to make cellulose which is what cell walls are made out of
• where does photosynthesis take place

  within chloroplasts
• what type of reaction is photosynthesis

  an endothermic reaction which takes in light energy
• what is chlorophyll


  a pigment found in chloroplasts that absorbs light
• what are photosynthetic organisms 


  the main producers of food and therefore biomass in the environment
• what factors affect the rate of photosynthesis

  temperature , light intensity , carbon dioxide concentration
• what is a limiting factor

  a variable that limits the rate of a particular reaction
• how does temperature affect the rate of photosynthesis

  the higher temperature gives more energy to the enzymes involved in photosynthesis therefore the rate increases as the temperature rises

  the optimum temperature is around 25 degrees

  if the temperature becomes too high (around 45 degrees) . the enzymes becomes denatured and the rate of photosynthesis decreases
• draw a graph to show the effect of increasing temperature on the rate of photosynthesis

  graph

  
• explain how light intensity affects the rate of photosynthesis

  the rate of photosynthesis is directly proportional to light intensity , as light intensity increases, the rate of photosynthesis increases
• why does the rate of photosynthesis eventually plateau even if light intensity continues to increase

  another factor (temperature of co2 concentration) becomes limiting
• show the graph for effect of light intensity on the rate of photosynthesis

  graph

  
• how can the effect of light intensity on the rate of photosynthesis be measured in the lab

  using a light meter , using the inverse square law
• what is the inverse square law

  light intensity is inversely proportional to 1/distance squared
• why does the rate of photosynthesis decrease as the distance from the light source increases

  light intensity is inversely proportional to the square of the distance from the light source , thus , as the distance increases , the light intensity decreases and the rate of photosynthesis decreases
• how does carbon dioxide concentration affect the rate of photosynthesis

  as carbon dioxide concentration increases , the rate of photosynthesis increases
• why does the rate of photosynthesis eventually plateau even if c02 concentration continues to increase

  another factor becomes limiting
• draw a graph to show the affect of c02 concentration on photosynthesis

  graph